Field of the Invention
The present invention relates to a sealing device which prevents a fluid to be sealed in an inside of a machine from leaking out to an outside of a machine in a motor vehicle, a general machine and an industrial machine, and is provided with a structure in which a non-rotating seal lip is brought into slidable contact with a seal flange in a rotating side. The sealing device according to the present invention is used, for example, as a rotating oil seal which seals an oil in an inside of a machine in a field associated to the motor vehicle.
Description of the Conventional Art
As shown in FIGS. 13A and 13B, there has been conventionally known a sealing device 101 which seals so as to prevent a sealed fluid (oil) in a machine inner side A leaking out to a machine outer side B between a housing 51 and a rotating shaft 61 passing through a shaft hole 52 provided in the housing 51, the sealing device 101 being constructed by a combination of a slinger 111 which is installed to an outer periphery of a rotating shaft 61, and a lip seal member 121 which is installed to an inner periphery of the shaft hole 52 in the housing 51.
The slinger 111 is made of a rigid material such as a metal, integrally has a sleeve portion 112 which is fixed to an outer peripheral surface of the rotating shaft 61, and a flange portion 113 which is provided in one end of the sleeve portion 112, and is provided in a machine outer side end face 113a of the flange portion 113 with a thread groove 114 exerting a fluid pumping action caused by a centrifugal force when the rotating shaft 61 rotates.
On the other hand, the lip seal member 121 has an attachment ring 122 which is fixed to an inner peripheral surface of the shaft hole 52 in the housing 51, and a rubber-like elastic body 123 which is fitted to the attachment ring 122, and is provided with a seal lip (an end face lip) 124 which slidably comes into close contact with the machine outer side end face 113a of the flange portion 113 in the slinger 111, by the rubber-like elastic body 123.
In recent years, a development of fuel efficient cars has been accelerated in a motor vehicle industry due to an environmental problem, and torque reduction at a time of rotating is listed up as needs for an oil seal for an engine. Under such a condition, according to the sealing device 101 having the end face lip structure shown in FIG. 13, the low torque can be achieved in comparison with a sealing device having a general radial lip structure.